| Structural strengthening methods | Key features of the strengthening methods | The practicability of the strengthening method |
| Enlarging section reinforcement method (reinforcement method of outsourced concrete sleeve)
| It can increase the bearing capacity and stiffness of members, reduce the slenderness ratio and axial compression ratio of columns, and lower the cost of reinforcement, but the wet operation time is long and the construction space is affected. | It is practical and effective, but if we use shotcrete or pressure grouting construction, we should consider whether local technology is guaranteed when examining and approving. |
Replacement concrete reinforcement method | It can solve the problem of reinforced concrete with insufficient strength or serious defects. The cost of reinforcement is low, but the wet working time is long | It is practical and effective, but the work of eliminating the original concrete is heavy and should be carefully operated to cause local damage. |
External bonded steel plate method (wet outsourced steel plate method) | It can greatly improve the bearing capacity and seismic capacity of the components, and has good ductility | Practical and effective, it is most suitable for reinforcement of heavy structure, large-span structure and important structures. |
Dry outsourced steel plate method | Construction is simple, wet operation is little, and the bearing capacity and seismic capacity of members can be improved, but the increase is not as big as that of wet type outsourcing steel, and the cost is also high. | Practical and effective, it is most suitable for reinforcement of heavy structure, large-span structure and important structures. Especially for reinforcement works which do not permit the use of adhesives and cultural relics and historical buildings with reversible requirements. |
Steel plate strengthening method (external plate plate method)
| It can improve the bearing capacity of the flexural and tensile members and the seismic capacity of the column, but it is not suitable for the reinforcement of the super reinforcement section of the beam; the wet operation is very few and does not affect the normal use of the building during the reinforcement construction; it does not affect the building space. | It is practical, effective and widely applied, but it is necessary to use high quality glue to get the reinforcement effect. |
Strengthening method of adhesive fiber reinforced polymer(FRP) composite material | It can improve the bearing capacity and aseismic ability of the components of various forces, and does not increase the weight of the structure, does not affect the space of building use; it is resistant to corrosion; but it needs special fire prevention treatment | The weight is light and has no effect on the structure. High comprehensive benefit. |
Stainless steel wire mesh - Surface reinforcement method of polymer mortar | It can improve the bearing capacity and seismic capacity of walls, columns and beams, and has no significant impact on building space, corrosion resistance and moisture resistance, but the cost is very high. | Effective, but only for buildings with important construction and special requirements. |
External prestressing reinforcement method | It can improve the bearing capacity, stiffness and crack resistance of the structure and components, but the concrete with large shrinkage and creep will affect the reinforcement effect, and has a certain effect on the appearance of the reinforced structure. | It is practical and effective, especially for large span, heavy duty and high stress and high strain states. |
Adding support and reinforcement method | The force is clear, safe and reliable, and the cost of reinforcement is low, but it significantly affects the space and appearance of building. | It is practical and effective, especially for cultural relics and historical buildings with reversible requirements. |
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